Re: [PATCH] powerpc/powernv: Move SCOM access code into powernv platform

[Andrew Donnellan]

On 8/5/19 10:27 pm, Michael Ellerman wrote:

Andrew Donnellan <a...@linux.ibm.com> writes:

The powernv platform is the only one that directly accesses SCOMs. Move the
support code to platforms/powernv, and get rid of the PPC_SCOM Kconfig
option, as SCOM support is always selected when compiling for powernv.

This code was used on WSP / A2, back in the past which is why it
originally lived in sysdev.

This also means that the Kconfig item for CONFIG_SCOM_DEBUGFS will actually
show up in menuconfig, as previously it was the only labelled option in
sysdev/Kconfig and wasn't actually in a menu.

Signed-off-by: Andrew Donnellan <a...@linux.ibm.com>
---
  arch/powerpc/include/asm/scom.h                   | 4 ++--

Can't scom.h move into powernv as well?

...looks like it can.

And do we even need the whole scom_controller abstraction?

Probably not. Looks like there's some completely dead code in there too.

Will send a v2.

If we ever have another platform that needs it we can always bring it
back.

cheers

  arch/powerpc/platforms/powernv/Kconfig            | 5 ++++-
  arch/powerpc/platforms/powernv/Makefile           | 2 +-
  arch/powerpc/{sysdev => platforms/powernv}/scom.c | 0
  arch/powerpc/sysdev/Kconfig                       | 7 -------
  arch/powerpc/sysdev/Makefile                      | 2 --
  6 files changed, 7 insertions(+), 13 deletions(-)
  rename arch/powerpc/{sysdev => platforms/powernv}/scom.c (100%)

diff --git a/arch/powerpc/include/asm/scom.h b/arch/powerpc/include/asm/scom.h
index f5cde45b1161..acc6532a9a9e 100644
--- a/arch/powerpc/include/asm/scom.h
+++ b/arch/powerpc/include/asm/scom.h
@@ -23,7 +23,7 @@

#ifdef __KERNEL__

  #ifndef __ASSEMBLY__
-#ifdef CONFIG_PPC_SCOM
+#ifdef CONFIG_PPC_POWERNV

/*

   * The SCOM bus is a sideband bus used for accessing various internal
@@ -161,7 +161,7 @@ static inline int scom_write(scom_map_t map, u64 reg, u64 
value)
  }

-#endif /* CONFIG_PPC_SCOM */

+#endif /* CONFIG_PPC_POWERNV */
  #endif /* __ASSEMBLY__ */
  #endif /* __KERNEL__ */
  #endif /* _ASM_POWERPC_SCOM_H */
diff --git a/arch/powerpc/platforms/powernv/Kconfig 
b/arch/powerpc/platforms/powernv/Kconfig
index 850eee860cf2..938803eab0ad 100644
--- a/arch/powerpc/platforms/powernv/Kconfig
+++ b/arch/powerpc/platforms/powernv/Kconfig
@@ -12,7 +12,6 @@ config PPC_POWERNV
        select EPAPR_BOOT
        select PPC_INDIRECT_PIO
        select PPC_UDBG_16550
-       select PPC_SCOM
        select ARCH_RANDOM
        select CPU_FREQ
        select PPC_DOORBELL
@@ -47,3 +46,7 @@ config PPC_VAS
          VAS adapters are found in POWER9 based systems.

If unsure, say N.

+
+config SCOM_DEBUGFS
+       bool "Expose SCOM controllers via debugfs"
+       depends on DEBUG_FS
diff --git a/arch/powerpc/platforms/powernv/Makefile 
b/arch/powerpc/platforms/powernv/Makefile
index da2e99efbd04..4b1644150135 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -4,12 +4,12 @@ obj-y                 += idle.o opal-rtc.o opal-nvram.o 
opal-lpc.o opal-flash.o
  obj-y                 += rng.o opal-elog.o opal-dump.o opal-sysparam.o 
opal-sensor.o
  obj-y                 += opal-msglog.o opal-hmi.o opal-power.o opal-irqchip.o
  obj-y                 += opal-kmsg.o opal-powercap.o opal-psr.o 
opal-sensor-groups.o
+obj-y                  += opal-xscom.o scom.o

obj-$(CONFIG_SMP) += smp.o subcore.o subcore-asm.o

  obj-$(CONFIG_PCI)     += pci.o pci-ioda.o npu-dma.o pci-ioda-tce.o
  obj-$(CONFIG_CXL_BASE)        += pci-cxl.o
  obj-$(CONFIG_EEH)     += eeh-powernv.o
-obj-$(CONFIG_PPC_SCOM) += opal-xscom.o
  obj-$(CONFIG_MEMORY_FAILURE)  += opal-memory-errors.o
  obj-$(CONFIG_OPAL_PRD)        += opal-prd.o
  obj-$(CONFIG_PERF_EVENTS) += opal-imc.o
diff --git a/arch/powerpc/sysdev/scom.c b/arch/powerpc/platforms/powernv/scom.c
similarity index 100%
rename from arch/powerpc/sysdev/scom.c
rename to arch/powerpc/platforms/powernv/scom.c
diff --git a/arch/powerpc/sysdev/Kconfig b/arch/powerpc/sysdev/Kconfig
index e0dbec780fe9..7808d279ff1d 100644
--- a/arch/powerpc/sysdev/Kconfig
+++ b/arch/powerpc/sysdev/Kconfig
@@ -28,13 +28,6 @@ config PPC_MSI_BITMAP
  source "arch/powerpc/sysdev/xics/Kconfig"
  source "arch/powerpc/sysdev/xive/Kconfig"

-config PPC_SCOM

-       bool
-
-config SCOM_DEBUGFS
-       bool "Expose SCOM controllers via debugfs"
-       depends on PPC_SCOM && DEBUG_FS
-
  config GE_FPGA
        bool

diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile

index aaf23283ba0c..35d52d1d2fc0 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -51,8 +51,6 @@ ifdef CONFIG_SUSPEND
  obj-$(CONFIG_PPC_BOOK3S_32)   += 6xx-suspend.o
  endif

-obj-$(CONFIG_PPC_SCOM) += scom.o

-
  obj-$(CONFIG_PPC_EARLY_DEBUG_MEMCONS) += udbg_memcons.o

obj-$(CONFIG_PPC_XICS) += xics/

--
2.20.1

--
Andrew Donnellan              OzLabs, ADL Canberra
a...@linux.ibm.com             IBM Australia Limited